Summary: An overhaul in 2016 of the main U.S. chemical safety law, the Toxic Substances Control Act, required EPA to choose the first 10 chemicals for risk evaluation. 1,4-dioxane, one of the first 10 chemicals, is a chemical used in building materials, degreasers and other uses as well as a contaminant in a range of products. EPA has classified it as a likely carcinogen.

What kinds of products may use it?

  • Building materials such as cement, roofing, siding, and insulation
  • Film cement
  • All-purpose cleaners
  • Degreasers
  • Low-friction coating

Present as a trace contaminant in:

  • Children's toys and clothes
  • Detergents
  • Cosmetics
  • Personal care products (e.g., deodorants and shampoos)

What hazards does it pose?

  • Likely human carcinogen
  • Toxic to liver, kidney, and central nervous system
  • Toxicity to aquatic plants and invertebrates
  • Moderately persistent in the environment

Who may be exposed or most at risk?

  • Workers and occupational bystanders in 1,4-dioxane manufacturing and processing industries or using commercial products containing 1,4-dioxane
  • Consumers using products containing 1,4-dioxane
  • People that depend on water sources contaminated with 1,4-dioxane
  • People that live in environments contaminated with 1,4-dioxane

Production profile (2015)

  • U.S. manufacture (production and import): 1,059,980 lbs
  • Number of manufacturers: At least 2
  • Number of manufacturing sites: 4

What industries use it?

  • Organic and inorganic chemical manufacturing/synthesis (reactant, solvent, intermediate, or catalyst)
  • Plastics manufacturing
  • Construction materials manufacturing
  • Pharmaceuticals manufacturing
  • Animal or vegetable oil extraction
  • Solvent for dissolving various cellulose compounds, resins, oils, waxes, and fats
  • Printing

1,4-dioxane additional resources

Full list of EPA's first 10 chemicals under review

Chemical snapshot

Cleaning products
CAS Number: 123-91-1
1,4-dioxane can be present in cleaning products as a contaminant.

1,4-dioxane chemical structure
Chemical structure
Credit: Chem ID Plus data base under the U.S. National Library of Medicine.

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